13 Hefty Facts About How You Actually Lose Weight

No matter how enticing the promises of the latest fad diet sound, here's the simple truth about losing weight: it really boils down to more calories out than calories in. Protein or carb, whichever it may be -- the number of calories in your food is what adds up and can lead to weight gain (although balance in your diet is important for long-term health).

Curious to learn more facts about weight loss? Did you know that a pound of fat is about 3,600 calories, which is the equivalent of four chocolate bars or 14 slices of pizza? If walking one mile can burn about 100 calories, it can be eye-opening to do the math and find out what it takes to burn off the calories of our favorite foods. For example, if you eat a double-patty burger you'll need to walk about five and a half miles!

Which is more important for weight loss: diet or exercise? Is breakfast really the most important meal of the day, and is it a bad idea to eat a big dinner? You'll find the answers to these popular questions and more in the video above. We'll leave you with this scary fact about fat cells: you can gain more them, but you can never lose them.

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15 Breakfast Mistakes That Cause Weight Gain

We know breakfast is the most important meal of the day, but what we don't know about the morning meal could inadvertently be packing on the pounds! We consulted with health expert Dr. Lisa Davis, Vice President of Scientific and Clinical Affairs at Medifast, to expose 15 of the biggest breakfast no-nos.

When coworkers bring in treats, the office can become a calorie trap. Davis' advice? "Stop, get centered, take a deep breath, and focus on your health goals," she says. Which is better: the taste of a muffin or the feeling of reaching your goals?

You may think that gulping down a glass of OJ is a great way to start your day, but many store-bought varieties are packed with sugar. "A healthy serving of orange juice is about as much as you could squeeze out of one orange," Davis says. "A better idea may be to have a glass of water and eat the orange itself: Whole fruit offers you all the vitamins and minerals of the juice, along with tummy-filling fiber that can help tame hunger pangs until lunch."

Davis says pancakes and waffles are a no-no for breakfast, especially when accompanied by sugary syrup. "Instead, try a whole-grain cereal or toast, and try to get some protein in the form of low-fat or fat-free yogurt, lean meat, or egg whites," she says. "You'll feel fuller for longer."

Breakfast pastries are delicious, but when you're faced with treats first thing in the morning, try your best to resist. "Sugary cereals, toaster pastries, bagels, and cinnamon rolls are tempting, but they're likely to cause a spike in blood sugar, followed by a low-energy crash and hunger, which can cause a snack attack by mid-morning," Davis says.

You don't have to give up your morning cup of Joe, even if you're vying for a healthier diet. "Unless you have sensitivity to caffeine or a medical condition that makes it unwise to consume it, coffee can be a delicious and natural way to boost your mood and your brain function," Davis says. "If you need more than a cup or two to get going in the morning, you may be sleep-deprived. Coffee is not a substitute for actual zz's."

"It's what you add to coffee that can add pounds and inches," Davis says. "Sugar, flavored syrups, whipped cream, and half-and-half can turn a simple cup of coffee into a real calorie-bomb, and if you have one or more each day, those calories will add up. Subtract a little of the sugar and fat gradually and work toward enjoying your morning brew as close to ‘naked' as you can make it."

If you're often in a rush to get to work and skip breakfast, stock up on healthy snacks. "The key to healthy eating is planning ahead," Davis says. "It makes sense to keep nutritious, non-sugary pick-me-ups in your desk drawer or in the office fridge."

A serving each of low-fat protein, whole fruit or vegetables, and whole-grain bread or cereal is a great way to get your body and mind prepared for the demands of your day. However, you need to make sure that the number of calories you take in at breakfast works within your overall daily calorie target." Not sure what one serving looks like? Use these tricks to make it easy to stay on track.

"Although they're high in fat and calories, a handful of peanuts from the vending machine will at least give you some protein and fiber, which will keep you feeling full longer than a doughnut will," Davissays. "If you can, skip out to a convenience store and grab a nonfat sugar-free yogurt, a string cheese stick, whole fruit, or a small protein bar."

"There's an old saying that goes, ‘Eat breakfast like a king, lunch like a prince, and dinner like a pauper,'" Davis says. Keep this quote in mind throughout the day, and you'll be on your way to healthy weight loss in no time!

Granola and breakfast bars often serve as quick on-the-go meals, but many of them have as many calories as dessert! "Most commercial granola bars are basically oatmeal cookies in disguise, with a lot more sugar than you need," Davis says. "A little natural peanut butter on a folded slice of whole-grain bread is better. Make a couple of these mini sandwiches in advance and keep one in your fridge at home, and one at work."

Whether you're noshing on breakfast or brunch, remember your first meal of the day should nourish you, not knock you out (and add excess calories)! "Go easy on the alcohol," Davis says. "That ounce of vodka in your Bloody Mary adds about 100 calories."

Even if you wake up feeling full from the previous night's dinner, try to munch on a little something in the a.m. "Heavy meals late in the evening are likely to overwhelm your digestive system and can even interfere with a restful sleep," Davis says. "But if you indulge once in a while, keep in mind that even if you feel full the next morning, you haven't had any nourishment since you went to bed. Skipping meals can cause your metabolism to slow down, so if you can, try a slice of plain, whole-grain toast and hot tea, or some apple slices with plain, non-fat yogurt."